Automatic-brake pulley-block



(No Modl.) 2 Sheets-Sheet 1. H. W; SEAMAN.

AUTOMATIC BRAKE PULLBY BLOCK. No. 468,901. Patented Feb. 16,1892.

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(No Model.) I 2 Sheets-Sheet 2. H. SEAMAN. AUTOMATIC BRAKE PULLEY BLOCK.

Patented Feb. 16, 1892.

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UNITED STATES PATENT OFFICE.

HORACE W. SEAMAN, OF MILLPORT, ASSIGNOR TO JAMES M. ROSE, OF A SYRACUSE, NEW YORK.

AUTOMATIC-BRAKE, PU LLEY-BLOCK.

SPECIFICATION forming part of Letters Patent No. 468,901, dated February 16, 18 92. Application filed May 25, 1891. Serial No. 394.088. (No model.)

To aZZ whom it may concern:

Be it known that I, HORACE W. SEAMAN, a citizen of the United States of America, residing at Millport, in the county of Chemung and State of New York, have invented a new and useful Automatic-Brake Pulley-Block, of which the following is a specification.

My invention relates to improvements in automatic brakes for pulley-blocks,in which by means of a rack and pinion, (the pinion having cogs on only about one-half of its periphery, the other one-half being corrugated,) the pinion being turned by a shaft having a weighted lever securedto it, in combination with the ordinary pulley-block, the rope used in raising a weight is locked and securely held or gripped whenever the power used in raising the weight is suspended or Withdrawn, thereby retaining the weight in the position in which it was when the power was suspended or withdrawn. I attain these objects by the mechanism illustrated in the accompanying drawings, in which- 7 Figure 1 is a side view of the ordinary pulley-block combined with the rack,pinion, and lever and illustrates the automatic-brake pul-. ley-block herein described when complete. Fig. 2 is a side or end view of the rack broken from the pulley-block proper. Fig. 3 is a view of the weighted lever. Fig. 4t is a side view of the automatic-brake pulley-block with one side of the case removed, showing the relative position of the rack, pinion, and pulley and the automatic locking of the rope by the action of the weighted lever upon the pinion.

My invention consists in the detailed construction and arrangement of the parts, all as hereinafter more fully described, set forth, and pointed out. V

Like letters refer to like parts throughout the several drawings.

A represents the case of the pulley-block.

B is the extension-arm, being a part of the case, and is provided with the slots a in both sides of the case.

0 is the rack, and is preferably made so that the one side of the case, arm-case, and rack form but a single piece.

D is the pinion, which is turned by the shaft Z), which passes through the slots a and holds the pinion in position and conjunction with the rack.

E is the weighted lever, which is provided with the square hole a to fit upon the squared end of the shaft b, and also is provided with the hole d in the end of the lever for a trip or unlocking-cord.

F is the sheave.

It will be observed that the pinion D is provided with cogs only on one half of its periphery, the other half being corrugated or grooved longitudinally Where it comes in contact with the rope used in raising a weight.

Having pointed out the various parts of my invention, the operation thereof in combination is as follows: The weight to be hoisted is suspended from the rope atXand the power is applied at Y. As the Weight is being hoisted the rope moves around the sheave F in the direction of the arrow and the pinion D is thrown or raised up in the rack O and does not grip the rope against the sheave. WVhen, however, the power is suspended or withdrawn, the gravity of the weight draws the rope in the direction opposite to the arrow and the corrugated or grooved surface of the pinion D is brought by the weighted lever E into strong friction contact with the rope,

whereby the rope is firmly wedged or gripped between the pinion D and the sheave F, as best shown in Fig. 4, and thereby secures the rope, so that the weight is held in the position it was when the power was suspended or wholly withdrawn. The grip upon the rope may be removed either by pulling on the unlocking-cord e or by again applying the power to the rope at Y. t 7 Y Having fully and particularly described the nature and object of my invention and the manner in which the same is to be performed and operated,'l declare that what I claim as my invention, and desire-to secure by Letters Patent, is

The combination, in an automatic-brake pulley-block, of the ordinary pulley-block, the extension-arm B of the case, said arm being provided with slots a, the rack O, the pinion HORACE w. SEAMAN. n s.]

Witnesses:

GEO. E. CONGDON, JAMEs MILLER. 

